Justification of Red List Category
This species is certainly rare and has not been found during survey work in Cameroon over the past few years. However, the reasons for its rarity are unclear and there may be specific habitat requirements, as yet unknown, limiting its distribution. The population is likely to be small and probably declining, owing to habitat loss and/or alteration, and it is therefore classified as Endangered.
The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals.
The population is suspected to be in decline at an unquantified rate, owing to habitat loss or alteration, although it is not known what processes might be limiting the species's abundance or causing declines, and this requires detailed study.
Ploceus batesi is a rarely-recorded species from southern and western Cameroon, occurring in a narrow belt from Limbe, at the foot of Mt Cameroon (Taylor 1981) (although the observation at Limbe was not confirmed), east to Moloundou (Collar and Stuart 1985). In recent years, it has only been seen twice near the Dja Faunal Reserve (at Somalomo on the north-west boundary of the Reserve in 1995, and at Shwani, 12 km from Somalomo, in 1996) (R. Fotso in litt. 1999) and remains known from only a few localities, including Mt Kupe (two possible records in 1990, but none since, despite intensive searches). In 1998-2001, surveys in western and south-eastern Cameroon failed to relocate the species (F. Dowsett-Lemaire in litt. 2007).
It occurs in lowland rainforest, although all recent records come from secondary forest and forest edge, particularly degraded forest around villages (R. Fotso in litt. 1999, F. Dowsett-Lemaire in litt. 1999, 2000). It has been recorded on Mt Kupe up to 900 m. In 1979, a single bird was observed moving in a zig-zag manner up a creeper-covered tree-trunk (Taylor 1981), and it has been observed recently foraging under the canopy (R. Fotso in litt. 1999). It occurs singly and in pairs, and one record was in a mixed-species flock; it appears to forage on insects, bark-gleaning in the manner of Preuss's Weaver P. preussi, with which it could conceivably compete.
Since it is a bark-gleaning species it may be in competition with Preuss's Weaver P. preussi (F. Dowsett-Lemaire in litt. 1999, 2000). Despite the records from secondary habitat, its rarity may be attributable to the loss of some specific habitat feature. A plan for a 70,000 ha palm oil plantation is underway and threatens to significantly fragment large areas of suitable habitat in southwestern Cameroon (Linder et al. 2012).
Conservation Actions Underway
The Dja Faunal Reserve is a protected area.
12-14 cm. Small forest weaver. Male has bright chestnut head with contrasting black throat which extends in band to nape. Small yellow collar separates head from rich olive-green upperparts. Bright golden-yellow underparts except for black on throat. Female very similar but has black, not chestnut, on head and lacks black throat and nape configuration of male. Voice Undescribed.
Text account compilers
Bird, J., Butchart, S., Ekstrom, J., Shutes, S., Symes, A., Taylor, J. & Westrip, J.
Bowden, C., Dowsett-Lemaire, F., Fotso, R., Whytock, R. & Dowsett, R.
BirdLife International (2020) Species factsheet: Ploceus batesi. Downloaded from http://www.birdlife.org on 19/09/2020. Recommended citation for factsheets for more than one species: BirdLife International (2020) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/09/2020.